I know this might not be the right section for this topic but I was wondering if any other stores besides a hobby shop would carry the fine sandpaper sheets? Also, what exactly is wet sanding and can you use any sandpaper for it? Just need a little help with sandpaper lol

I just finished my first model and I'm not happy with it at all. I was wondering if I could break the whole thing down and strip everything to start over? I used the crappy testors tube glue(red tube) and the testors enamel paint. How do I begin?